The vehicle such as an automobile corrects inner and outer wheels at the time of turn based on a yaw rate of the vehicle in order to correct a wheel speed. Herein, a value of the yaw rate of the vehicle differs depending on whether the vehicle moves forward or backward even at the same vehicle speed. Therefore, a device for detecting whether the vehicle moves forward or backward is proposed in order to correctly calculate the yaw rate of the vehicle.
For example, the patent literature 1 discloses a forward movement judging device including rotational number detecting means for detecting a rotational number of an engine and a vehicle speed detecting means for detecting a vehicle speed. The forward movement judging device estimates a transmission ratio of the traveling vehicle by a transmission ratio estimating means based on detection results of the vehicle speed and the engine rotational number, judges that the vehicle is traveling forward by a forward movement judging means when the estimated transmission ratio is the transmission ratio on a side of a high rotational output which is the closest to the transmission ratio at the time of the backward movement or higher than the same out of a plurality of transmission ratios of a transmission device, and judges that the vehicle travels forward until the vehicle stops even when the transmission ratio changes thereafter in order to provide the forward movement judging device of the vehicle capable of easily and surely judging whether the vehicle travels forward.
Also, the patent literature 2 discloses a behavior control device that inhibits an execution of a behavior control for forward movement. The behavior control device judges whether the vehicle is in a backward movement state based on a vehicle speed and a shift position, judges whether there is a possibility that the vehicle is in the backward movement state when it is judged that the vehicle is not in the backward movement state, judges whether the vehicle is in a forward movement state when it is judged that there is possibility that the vehicle is in the backward movement state, allows execution of behavior control for the forward movement by setting a flag to 1 when it is judged that the vehicle is in the forward movement state and resetting the flag to 0 when it is judged that the vehicle is not in the forward movement state.
Patent Literature 1: Japanese Patent Application Laid-open No. 2002-236133
Patent Literature 2: Japanese Patent Application Laid-open No. 2000-318588